The present invention pertains to a process for the production of 17-hydroxysparteine by means of the oxidation of sparteine in an aqueous acid solution.
The recent discovery of the advantageous pharmacological effects of different sparteine derivatives (DE-OS 23 60 475) prepared initially from 17-hydroxysparteine has generated a need for a technically and economically reasonable process for the production of 17-hydroxysparteine. In a known process (M. Rink, K. Grabowski, Arch. Pharm. 61 (1956), 695) sparteine is oxidized by means of chromium trioxide. The processing of the reaction mixture results in substantial amounts of aqueous solutions of chromium.sup.III and chromium.sup.VI salts, from which the very toxic chromic compounds may be separated only by means of expensive processes. Furthermore, the yield in 17-hydroxysparteine amounts to only 39%.
The oxidation of sparteine to 17-hydroxysparteine with the aid of the microorganism Trametes gibbosa is also known (K. Furuya, K. Aida, Y. Koiso, Chem. Pharm. Bull. 21 (1973), 231). This process operates with large volumes of liquid and is thus expensive, and it yields the desired 17-hydroxysparteine again in the relatively modest yield of 38%.
Oxidation with the ascorbic acid-iron.sup.II -oxygen system (F. Jaminet, J. Pharm. Belg. 13 (1958), 577), which is highly time consuming, is merely of an academic character; after several days of reaction, it converts only part of the sparteine introduced.